package com.example.lotterysystem.service.impl;
import java.util.ArrayList;
import java.util.Date;

import cn.hutool.core.util.StrUtil;
import com.example.lotterysystem.common.errorcode.ServiceErrorCodeConstants;
import com.example.lotterysystem.common.exception.ServiceException;
import com.example.lotterysystem.common.utils.JacksonUtil;
import com.example.lotterysystem.common.utils.RedisUtil;
import com.example.lotterysystem.controller.param.CreateActivityParam;
import com.example.lotterysystem.controller.param.CreatePrizeByActivityParam;
import com.example.lotterysystem.controller.param.CreateUserByActivityParam;
import com.example.lotterysystem.controller.param.PageParam;
import com.example.lotterysystem.dao.dataobject.ActivityDO;
import com.example.lotterysystem.dao.dataobject.ActivityPrizeDO;
import com.example.lotterysystem.dao.dataobject.ActivityUserDO;
import com.example.lotterysystem.dao.dataobject.PrizeDO;
import com.example.lotterysystem.dao.mapper.*;
import com.example.lotterysystem.service.ActivityService;
import com.example.lotterysystem.service.dto.ActivityDTO;
import com.example.lotterysystem.service.dto.ActivityDetailDTO;
import com.example.lotterysystem.service.dto.CreateActivityDTO;
import com.example.lotterysystem.service.dto.PageListDTO;
import com.example.lotterysystem.service.enums.ActivityPrizeStatusEnum;
import com.example.lotterysystem.service.enums.ActivityPrizeTiersEnum;
import com.example.lotterysystem.service.enums.ActivityStatusEnum;
import com.example.lotterysystem.service.enums.ActivityUserStatusEnum;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.util.CollectionUtils;
import org.springframework.util.StringUtils;

import java.util.List;
import java.util.Optional;
import java.util.stream.Collectors;
import java.util.stream.Stream;

@Service
public class ActivityServiceImpl implements ActivityService {


    private static final Logger logger = LoggerFactory.getLogger(ActivityServiceImpl.class);

    /**
     * 活动缓存前置，为了区分业务
     */
    private final String ACTIVITY_PREFIX = "ACTIVITY_";

    /**
     * 活动缓存过期时间（s）
     */
    private final Long ACTIVITY_TIMEOUT = 60 * 60 * 24 * 3L;


    @Autowired
    private UserMapper userMapper;

    @Autowired
    private PrizeMapper prizeMapper;

    @Autowired
    private ActivityMapper activityMapper;

    @Autowired
    private ActivityPrizeMapper activityPrizeMapper;

    @Autowired
    private ActivityUserMapper activityUserMapper;

    @Autowired
    private RedisUtil redisUtil;



    @Override
    @Transactional(rollbackFor = Exception.class)   //涉及多张表
    public CreateActivityDTO createActivity(CreateActivityParam param) {
        // 校验活动信息是否正确
        checkActivityInfo(param);

        //保存活动信息
        ActivityDO activityDO = new ActivityDO();
        activityDO.setActivityName(param.getActivityName());
        activityDO.setDescription(param.getDescription());
        activityDO.setStatus(ActivityStatusEnum.RUNNING.name() );
        activityMapper.insert(activityDO);

        //保存活动关联的奖品信息
        List<CreatePrizeByActivityParam> prizeParams = param.getActivityPrizeList();
        List<ActivityPrizeDO> activityPrizeDOList = prizeParams
                .stream()
                .map(prizeParam ->{
                    ActivityPrizeDO activityPrizeDO = new ActivityPrizeDO();
                    activityPrizeDO.setActivityId(activityDO.getId());
                    activityPrizeDO.setPrizeId(prizeParam.getPrizeId());
                    activityPrizeDO.setPrizeAmount(prizeParam.getPrizeAmount());
                    activityPrizeDO.setPrizeTiers(prizeParam.getPrizeTiers());
                    activityPrizeDO.setStatus(ActivityPrizeStatusEnum.INIT.name());
                    return activityPrizeDO;
                }).collect(Collectors.toList());
        activityPrizeMapper.batchInsert(activityPrizeDOList);

        //保存活动关联的人员信息
        List<CreateUserByActivityParam> userParams = param.getActivityUserList();
        List<ActivityUserDO> activityUserDOList = userParams
                .stream()
                .map(userParam -> {
                    ActivityUserDO activityUserDO = new ActivityUserDO();
                    activityUserDO.setActivityId(activityDO.getId());
                    activityUserDO.setUserId(userParam.getUserId());
                    activityUserDO.setUserName(userParam.getUserName());
                    activityUserDO.setStatus(ActivityUserStatusEnum.INIT.name());
                    return activityUserDO;
                }).collect(Collectors.toList());
        activityUserMapper.bathInsert(activityUserDOList);
        //整合完整的活动信息，存放到redis
        //activityId: ActivityDetailDTO: 活动 + 奖品 + 人员

        //先获取奖品基本属性列表
        //获取需要查询的奖品id
        List<Long> prizeIds = param.getActivityPrizeList()
                .stream()
                .map(CreatePrizeByActivityParam::getPrizeId)
                .distinct()
                .collect(Collectors.toList());
        List<PrizeDO> prizeDOList = prizeMapper.batchSelectByIds(prizeIds);
        ActivityDetailDTO detailDTO = convertToActivityDetailDTO(activityDO, activityUserDOList,
                prizeDOList, activityPrizeDOList);
        cacheActivity(detailDTO);

        //构造返回
        CreateActivityDTO createActivityDTO = new CreateActivityDTO();
        createActivityDTO.setActivityId(activityDO.getId());
        return createActivityDTO;
    }




    @Override
    public PageListDTO<ActivityDTO> findActivityList(PageParam param) {
        // 获取总量
        int total = activityMapper.count();

        //获取当前页列表
        List<ActivityDO> activityDOList = activityMapper.selectActivityList(param.offset(), param.getPageSize());
        List<ActivityDTO> activityDTOList = activityDOList
                .stream()
                .map(activityDO -> {
                    ActivityDTO activityDTO = new ActivityDTO();
                    activityDTO.setActivityId(activityDO.getId());
                    activityDTO.setActivityName(activityDO.getActivityName());
                    activityDTO.setDescription(activityDO.getDescription());
                    activityDTO.setStatus(ActivityStatusEnum.forName(activityDO.getStatus()));
                    return activityDTO;
                }).collect(Collectors.toList());
        return new PageListDTO<>(total, activityDTOList);
    }


    @Override
    public ActivityDetailDTO getActivityDetail(Long activityId) {

        if(null == activityId){
            logger.warn("查询活动详细信息失败， activityId 为空！");
            return null;
        }
        //查询 redis
        ActivityDetailDTO detailDTO = getActivityFromCache(activityId);
        if(null != detailDTO){
            logger.info("查询活动详细信息成功！ detailDTO={}",
                    JacksonUtil.writeValueAsString(detailDTO));
            return detailDTO;
        }
        //如果 redis不存在，查表
        //活动表
        ActivityDO activityDO = activityMapper.selectById(activityId);
        //活动奖品表
        List<ActivityPrizeDO> apDOList = activityPrizeMapper.selectByActivityId(activityId);
        //活动人员表
        List<ActivityUserDO> auDOList = activityUserMapper.selectByActivityId(activityId);
        //奖品表：先获取要查询的奖品id
        List<Long> prizeIds = apDOList
                .stream()
                .map(ActivityPrizeDO::getPrizeId)
                .collect(Collectors.toList());
        List<PrizeDO> pDOList = prizeMapper.batchSelectByIds(prizeIds);
        //整合活动详细信息，存放 redis
        detailDTO = convertToActivityDetailDTO(activityDO, auDOList,pDOList, apDOList);
        cacheActivity(detailDTO);
        //返回
        logger.info("返回给前端的 detailDTO: {}", JacksonUtil.writeValueAsString(detailDTO));
        return detailDTO;
    }

    @Override
    public void cacheActivity(Long activityId) {
        if(null == activityId){
            logger.warn("要缓存的活动id为空！");
            throw new ServiceException(ServiceErrorCodeConstants.CACHE_ACTIVITY_ID_IS_EMPTY);
        }

        //查询表数据：活动表、关联奖品表、关联人员表、奖品信息表
        //如果 redis不存在，查表
        //活动表
        ActivityDO activityDO = activityMapper.selectById(activityId);
        if(null == activityDO){
            logger.warn("要缓存的活动id有误！");
            throw new ServiceException(ServiceErrorCodeConstants.CACHE_ACTIVITY_ID_ERROR);
        }

        //活动奖品表
        List<ActivityPrizeDO> apDOList = activityPrizeMapper.selectByActivityId(activityId);
        //活动人员表
        List<ActivityUserDO> auDOList = activityUserMapper.selectByActivityId(activityId);
        //奖品表：先获取要查询的奖品id
        List<Long> prizeIds = apDOList
                .stream()
                .map(ActivityPrizeDO::getPrizeId)
                .collect(Collectors.toList());
        List<PrizeDO> pDOList = prizeMapper.batchSelectByIds(prizeIds);
        //整合活动详细信息，存放 redis
        //整合完整的活动信息并缓存
        cacheActivity(convertToActivityDetailDTO(activityDO, auDOList,pDOList, apDOList));
    }


    /**
     * 缓存完整的活动信息
     * @param detailDTO
     */
    private void cacheActivity(ActivityDetailDTO detailDTO) {
        // key: ACTIVITY_activityId
        // value: ActivityDetailDTO(JSON)
        if(null == detailDTO || null == detailDTO.getActivityId()){
            logger.warn("要缓存的活动信息不存在！");
            return;
        }

        try{
            redisUtil.set(ACTIVITY_PREFIX + detailDTO.getActivityId(),
                    JacksonUtil.writeValueAsString(detailDTO),
                    ACTIVITY_TIMEOUT);
        }catch (Exception e){
            logger.error("缓存活动异常：ActivityDetailDTO={}",
                    JacksonUtil.writeValueAsString(detailDTO),
                    e);
        }
    }

    /**
     * 根据活动id从缓存中获取活动详细信息
     * @param activityId
     * @return
     */
    private ActivityDetailDTO getActivityFromCache(Long activityId){
        if(null == activityId){
            logger.warn("获取缓存活动数据的activityId为空！");
            return null;
        }

        try{
            String str = redisUtil.get(ACTIVITY_PREFIX + activityId);
            if(!StringUtils.hasText(str)){
                logger.info("要获取的缓存数据为空！ key={}", ACTIVITY_PREFIX + activityId);
                return null;
            }
            ActivityDetailDTO detailDTO = JacksonUtil.readValue(str, ActivityDetailDTO.class);
            return detailDTO;
        }catch (Exception e){
            logger.error("从缓存中获取活动信息异常：key={}", ACTIVITY_PREFIX + activityId, e);
            return null;
        }
    }


    /**
     * 根据基本DO整合完整的互动信息ActivityDetailDTO
     * @param activityDO
     * @param activityUserDOList
     * @param prizeDOList
     * @param activityPrizeDOList
     * @return
     */
    private ActivityDetailDTO convertToActivityDetailDTO(ActivityDO activityDO,
                                                         List<ActivityUserDO> activityUserDOList,
                                                         List<PrizeDO> prizeDOList,
                                                         List<ActivityPrizeDO> activityPrizeDOList) {
        ActivityDetailDTO detailDTO = new ActivityDetailDTO();
        detailDTO.setActivityId(activityDO.getId());
        detailDTO.setActivityName(activityDO.getActivityName());
        detailDTO.setDesc(activityDO.getDescription());
        detailDTO.setStatus(ActivityStatusEnum.forName(activityDO.getStatus()));

        //activityPrizeDO: {prizeId, amount, status}, {prizeId, amount, status}
        //prizeDO: {prizeid, name……},{prizeid, name……},{prizeid, name……}
        List<ActivityDetailDTO.PrizeDTO> prizeDTOList = activityPrizeDOList
                .stream()
                .map(activityPrizeDO -> {
                    ActivityDetailDTO.PrizeDTO prizeDTO = new ActivityDetailDTO.PrizeDTO();
                    prizeDTO.setPrizeId(activityPrizeDO.getPrizeId());
                    Optional<PrizeDO> optionalPrizeDO = prizeDOList.stream()
                            .filter(prizeDO -> prizeDO.getId().equals(activityPrizeDO.getPrizeId()))
                            .findFirst();

                    //如果PrizeDO为空，不执行当前方法,不为空才执行
                    optionalPrizeDO.ifPresent(prizeDO -> {
                        prizeDTO.setName(prizeDO.getName());
                        prizeDTO.setImageUrl(prizeDO.getImageUrl());
                        prizeDTO.setPrice(prizeDO.getPrice());
                        prizeDTO.setDescription(prizeDO.getDescription());
                    });

                    prizeDTO.setTiers(ActivityPrizeTiersEnum.forName(activityPrizeDO.getPrizeTiers()));
                    prizeDTO.setPrizeAmount(activityPrizeDO.getPrizeAmount());
                    prizeDTO.setStatus(ActivityPrizeStatusEnum.forName(activityPrizeDO.getStatus()));

                    return prizeDTO;
                }).collect(Collectors.toList());
        detailDTO.setPrizeDTOList(prizeDTOList);


        List<ActivityDetailDTO.UserDTO> userDTOList = activityUserDOList.stream()
                .map(activityUserDO -> {
                    ActivityDetailDTO.UserDTO userDTO = new ActivityDetailDTO.UserDTO();
                    userDTO.setUserId(activityUserDO.getUserId());
                    userDTO.setUserName(activityUserDO.getUserName());
                    userDTO.setStatus(ActivityUserStatusEnum.forName(activityUserDO.getStatus()));


                    return userDTO;
                }).collect(Collectors.toList());
        detailDTO.setUserDTOList(userDTOList);
        return detailDTO;
    }

    /**
     * 校验活动有效性
     * @param param
     */
    private void checkActivityInfo(CreateActivityParam param) {
        if(null == param){
            throw new ServiceException(ServiceErrorCodeConstants.CREATE_ACTIVITY_INFO_IS_EMPTY);
        }

        //人员id在人员表中是否存在
        List<Long> userIds = param.getActivityUserList()
                .stream()
                .map(CreateUserByActivityParam::getUserId)
                .distinct() //去重
                .collect(Collectors.toList());
        List<Long> existUserIds = userMapper.selectExistByIds(userIds);
        if(CollectionUtils.isEmpty(existUserIds)){
            throw new ServiceException(ServiceErrorCodeConstants.ACTIVITY_USER_ERROR);

        }
        userIds.forEach(id ->{
            if(!existUserIds.contains(id)){
                throw new ServiceException(ServiceErrorCodeConstants.ACTIVITY_USER_ERROR);
            }
        });

        //奖品id在奖品表中是否存在
        List<Long> prizeIds = param.getActivityPrizeList()
                .stream()
                .map(CreatePrizeByActivityParam::getPrizeId)
                .distinct()
                .collect(Collectors.toList());
        List<Long> existPrizeIds = prizeMapper.selectExistByIds(prizeIds);
        prizeIds.forEach(id -> {
            if(!existPrizeIds.contains(id)){
                throw new ServiceException(ServiceErrorCodeConstants.ACTIVITY_PRIZE_ERROR);
            }
        });

        //人员数量至少大于等于奖品数量
        int userAmount = param.getActivityUserList().size();
        long prizeAmount = param.getActivityPrizeList()
                .stream()
                .mapToLong(CreatePrizeByActivityParam::getPrizeAmount)
                .sum();
        if(userAmount < prizeAmount){
            throw new ServiceException(ServiceErrorCodeConstants.USER_PRIZE_AMOUNT_ERROR);
        }


        //校验活动等级有效性
        param.getActivityPrizeList().forEach(prize ->{
            if(null == ActivityPrizeTiersEnum.forName(prize.getPrizeTiers())){
                throw new ServiceException(ServiceErrorCodeConstants.ACTIVITY_PRIZE_TIERS_ERROR);
            }
        });
    }
}
